1. Field of the Invention
The present invention pertains to the field of soft tissue excisional biopsy devices and methods. In particular, the present invention relates to the field of devices and methods for excising suspicious lesions from soft tissue, such as breast tissue.
2. Description of the Related Art
Breast cancer is a major threat and concern to women. Early detection and treatment of suspicious or cancerous lesions in the breast has been shown to improve long-term survival of the patient. The trend is, therefore, to encourage women not only to perform monthly self-breast examination and obtain a yearly breast examination by a qualified physician, but also to undergo annual screening mammography commencing at age 40. Mammography is the only screening modality available today that can detect small, nonpalpable lesions. These nonpalpable lesions may appear as opaque densities relative to normal breast parenchyma and fat or as clusters of microcalcifications.
The conventional method for diagnosing, localizing and excising nonpalpable lesions detected by mammography generally involves a time-consuming, multi-step process. First, the patient goes to the radiology department where the radiologist finds and localizes the lesion either using mammography or ultrasound guidance. Once localized, a radio-opaque wire is inserted into the breast. The distal end of the wire may include a small hook or loop. Ideally, this is placed adjacent to the suspicious area to be biopsied. The patient is then transported to the operating room. Under general or local anesthesia, the surgeon performs a procedure called a needle-localized breast biopsy. In the needle-localized breast biopsy, the surgeon, guided by the wire previously placed in the patient""s breast, excises a mass of tissue around the distal end of the wire. The specimen is sent to the radiology department where a specimen radiograph is taken to confirm that the suspicious lesion is contained within the excised specimen. Meanwhile, the surgeon, patient, anesthesiologist and operating room staff, wait in the operating room for confirmation of that fact from the radiologist before the operation is completed. The suspicious lesion should ideally be excised in toto with a small margin or rim of normal breast tissue on all sides. Obtaining good margins of normal tissue is extremely dependent upon the skill and experience of the surgeon, and often an excessively large amount of normal breast tissue is removed to ensure that the lesion is located within the specimen. This increases the risk of post-operative complications, including bleeding and permanent breast deformity. As 80% of breast biopsies today are benign, many women unnecessarily suffer from permanent scarring and deformity from such benign breast biopsies.
More recently, less invasive techniques have been developed to sample or biopsy the suspicious lesions to obtain a histological diagnosis. The simplest of the newer techniques is to attempt visualization of the lesion by external ultrasound. If seen by external ultrasound, the lesion can be biopsied while being continuously visualized. This technique allows the physician to see the biopsy needle as it actually enters the lesion, thus ensuring that the correct area is sampled. Current sampling systems for use with external ultrasound guidance include a fine needle aspirate, core needle biopsy or vacuum-assisted biopsy devices.
Another conventional technique localizes the suspicious lesion using stereotactic digital mammography. The patient is placed prone on a special table that includes a hole to allow the designated breast to dangle therethrough. The breast is compressed between two mammography plates, which stabilizes the breast to be biopsied and allows the digital mammograms to be taken. At least two images are taken 30 degrees apart to obtain stereotactic views. The x, y and z coordinates targeting the lesion are calculated by a computer. The physician then aligns a special mechanical stage mounted under the table that places the biopsy device into the breast to obtain the sample or samples. There are believed to be three methods available to biopsy lesions using a stereotactic table: (1) fine needle aspiration, (2) core needle biopsy and (3) vacuum-assisted core needle biopsy.
Fine needle aspiration uses a small gauge needle, usually 20 to 25 gauge, to aspirate a small sample of cells from the lesion or suspicious area. The sample is smeared onto slides that are stained and examined by a cytopathologist. In this technique, individual cells in the smears are examined, and tissue architecture or histology is generally not preserved. Fine needle aspiration is also very dependent upon the skill and experience of the operator and can result in a high non-diagnostic rate (up to about 83%), due to inadequate sample collection or preparation.
Core needle biopsy uses a larger size needle, usually 14 gauge to sample the lesion. Tissue architecture and histology are preserved with this method. A side-cutting device, consisting of an inner trough with an outer cutting cannula is attached to a spring-loaded device for a rapid semi-automated firing action. After the lesion is localized, local anaesthetic is instilled and a small incision is made in the skin with a scalpel. The device enters the breast and the needle tip is guided into the breast up to the targeted lesion. The device is fired. First, the inner cannula containing the trough rapidly penetrates the lesion. Immediately following this, the outer cutting cannula rapidly advances over the inner cannula cutting a sample of tissue off in the trough. The whole device is then removed and the sample retrieved. Multiple penetrations of the core needle through the breast and into the lesion are required to obtain an adequate sampling of the lesion. Over 10 samples have been recommended by some.
The vacuum-assisted breast biopsy system is a larger semi-automated side-cutting device. It is usually 11 gauge in diameter and is more sophisticated than the core needle biopsy device. Multiple large samples can be obtained from the lesion without having to reinsert the needle each time. A vacuum is added to suck the tissue into the trough. The rapid firing action of the spring-loaded core needle device is replaced with an oscillating outer cannula that cuts the breast tissue off in the trough. The physician controls the speed at which the outer cannula advances over the trough and can rotate the alignment of the trough in a clockwise fashion to obtain multiple samples.
If a fine needle aspirate, needle core biopsy or vacuum-assisted biopsy shows malignancy or a specific benign diagnosis of atypical hyperplasia, then the patient needs to undergo another procedure, the traditional needle-localized breast biopsy, to fully excise the area with an adequate margin of normal breast tissue. Sometimes the vacuum-assisted device removes the whole targeted lesion. If this occurs, a small titanium clip should be placed in the biopsy field. This clip marks the area if a needle-localized breast biopsy is subsequently required for the previously mentioned reasons.
Another method of biopsying the suspicious lesion utilizes a large end-cutting core device measuring 0.5 cm to 2.0 cm in diameter. This also uses the stereotactic table for stabilization and localization. After the lesion coordinates are calculated and local anesthesia instilled, an incision large enough is permit entry of the bore is made at the entry site with a scalpel. The breast tissue is cored down to and past the lesion. Once the specimen is retrieved, the patient is turned onto her back and the surgeon cauterizes bleeding vessels under direct vision. The incision, measuring 0.5 to larger than 2.0 cm is sutured closed.
The stereotactic table requires awkward positioning of the patient and may be extremely uncomfortable. The woman must lie prone during the entire procedure, which may be impossible for some patients. In addition, the lesion to be biopsied must be in the center working area of the mammography plates. This may be extremely difficult and uncomfortable for the patient if the lesion is very posterior near the chest wall or high towards the axilla.
The woman is subjected to increased radiation exposure as multiple radiographs are required throughout the course of the procedure to: (1) confirm that the lesion is within the working area of the mammography plates, (2) obtain the stereotactic coordinates (at least two views), (3) verify the positioning of the biopsy needle prior to obtaining tissue, and (4) verify that the lesion was indeed sampled. If any difficulty is encountered during the procedure, additional radiographic exposures are required to verify correction of the problem.
Using the core needle biopsy or vacuum-assisted device, bleeding is controlled only by manual pressure. Bleeding is generally not an issue with fine needle aspiration, but is a legitimate complication of the former two methods. Ecchymoses, breast edema and hematomas can occur. This causes increased post-procedural pain and delays healing. Rarely, the patient may require an emergency operation to control and evacuate a tense hematoma.
Another major concern is the possibility of tumor dissemination. The core needle biopsy and vacuum-assisted devices both cut into the tumor and carve out multiple samples for examination. While cutting into the tumor, cancerous cells may be dislodged. Cutting across blood vessels at the same time may allow the freed cancerous cells access to the blood stream, thus possibly seeding the tumor beyond its original locus. The long-term consequences of tumor seeding with the risk of bloodborne metastases are unknown at this time, as the techniques are relatively new. However, documented instances of cancerous cells seeding locally into needle tracks exist. There are numerous reports of metastases growing in needle tracks from previous biopsies of a cancerous mass. Most of these are from lung or liver cancers. However, at least one case of mucinous carcinoma of the breast growing in a needle track has been reported. The long-term consequences of neoplasm seeding into needle tracks are currently unknown, again because the techniques are relatively new. Some recommend excision of the entire needle track, including the skin entry site, during the definitive surgical procedure for a diagnosed cancer, whether it is a lumpectomy or a mastectomy. Others assume that with a lumpectomy, the post-operative radiation therapy will destroy any displaced cancer cells in the needle track. With the trend towards treating very small cancers only by excision and without a post-excision course of radiation therapy, the risk of cancer cells metastasizing and growing in needle tracks is very real.
The large core cutting device (0.5 cm to 2.0 cm) generally eliminates the risk of needle track seeding as it is designed to excise the lesion intact. A stereotactic table is required with the same inherent awkwardness for the patient, as discussed above. Bleeding is controlled, albeit manually, requiring that the patient wait until the end of the procedure to be turned over. Compression is used to stabilize the breast and localize the lesions. The breast, however, may be torqued and distorted between the compression plates such that when the plates are removed after the biopsy, the large core track left behind may not be straight, but actually tortuous. This can result in permanent breast deformity.
The location of the insertion site into the breast is dictated by the positioning of the breast in the machine and not by the physician. The entry site is usually away from the nipple-areolar complex and is usually located on the more exposed areas of the breast. For the fine needle aspirate, core biopsy and vacuum-assisted devices, the incision is usually very small and the scar almost unappreciable. However, in the case of the large core biopsy device (0.5 to 2.0 cm), a large incision is needed. Such a large incision often results in a non-aesthetically placed scar.
The newer conventional minimally invasive breast biopsy devices have improved in some ways the ability to diagnose mammographically detected nonpalpable lesions. These devices give the patient a choice as to how she wants the diagnosis to be made. Moreover, these devices are substantially less expensive than the older traditional needle-localized breast biopsy. They are not, however, the final solution. Due to the above-discussed problems and risks associated with compression, needle-track seeding, blood borne metastases, bleeding, radiation exposure and awkwardness of the stereotactic table, more refined devices and methods are needed to resolve these issues. Also, the conventional biopsy devices do not consider margins in their excisions and if cancer is diagnosed, the patient must undergo a needle-localized breast lumpectomy to ensure that adequate margins are removed around the cancer. Devices and methods, therefore, must address the problem of obtaining adequate margins so that a second procedure is not required. Margins, moreover, cannot be assessed while the breast is being compressed.
It is, therefore, an object of the present invention to provide devices and methods to efficiently and safely excise suspicious lesions from the breast. It is also an object of the present invention to provide devices and methods that remove the entire lesion intact with the minimum amount of normal tissue surrounding the lesion needed to provide adequate margins. It is a further object of the present invention to provide devices and methods that provide hemostasis in the breast to minimize complications of ecchymosis, hematoma formation, and breast edema. It is another object of the present invention to provide methods and devices to provide intra-tissue ultrasonic guidance to provide real time, in situ monitoring of the procedure. A still further object is to provide devices and methods that allow the physician to minimize the size of the incision through which the procedure is performed and to leave an aesthetically acceptable scar on the breast.
In accordance with the above-described objects and those that will be mentioned and will become apparent below, an embodiment of an excisional biopsy system according to the present invention comprises a tubular member including a proximal end and a distal end, the tubular member defining a first window near the distal end, and a first removable probe that includes a proximal portion including cutting tool extending means, a distal portion and a cutting tool near the distal portion, the first removable probe being configured to fit at least partially within the tubular member to enable the cutting tool to selectively bow out of and to retract within the first window when the cutting tool extending means are activated.
The first removable probe may further include a window slide and the proximal end may further include a window slide extending means, the window slide being configured to selectively cover a portion of the first window when the window slide extending means are activated. The cutting tool may include one of a thin ribbon sharpened on a leading edge thereof and a wire. The cutting tool may include an RF cutting tool and the first removable probe may be adapted to be connected to an RF power source. The cutting tool may include a monopolar or a bipolar RF cutting tool. The tubular member may include a first internal guide that is configured to enable the first removable probe to slide within the tubular member. The first removable probe may include a second internal guide, the second internal guide enabling the cutting tool to slide within the first removable probe when the cutting tool extending means are activated. The first removable probe may include a third internal guide, the third internal guide enabling the window slide to slide within the first removable probe when the window slide extending means are activated. The biopsy system may further include a second removable probe comprising a proximal section including a tissue collection device extending means and a distal section including a tissue collection device, the second removable probe being configured to fit at least partially within the tubular member to enable the tissue collection device to extend out of and to retract within the first window when the tissue collection device extending means are activated. Alternatively, the tubular member may define a second window near the distal end thereof, and the biopsy system may further include a second removable probe comprising a proximal section including a tissue collection device extending means and a distal section including a tissue collection device, the second removable probe being configured to fit at least partially within the tubular member to enable the tissue collection device to selectively extend out of and to retract within the second window when the tissue collection device extending means are activated.
The tissue collection device may include a thin ribbon or a wire, as well as a thin flexible sheet of material attached to the thin ribbon or wire, the thin flexible sheet at least partially encapsulating a tissue specimen as the thin ribbon or wire is extended and the tubular member rotated. The thin flexible sheet of material may include a bag attached to the ribbon or wire so as to open and close when the ribbon or wire is extended and retracted, respectively. The tissue collection device may include a thin ribbon or a wire, and a thin flexible sheet of material may be attached to the thin ribbon or wire, the thin flexible sheet at least partially encapsulating a tissue specimen as the thin ribbon or wire is extended and the tubular member rotated. The thin flexible sheet of material may include a bag attached to the thin ribbon or wire so as to open and close when the thin ribbon or wire is extended and retracted, respectively. The tubular member may include a first internal guide that is configured to enable one of the first and the second removable probe to slide within the tubular member until the cutting tool and/or the tissue collection device faces out of the first window. Similarly, the tubular member may include a second internal guide that is configured to enable the second removable probe to slide within the tubular member until the tissue collection device faces out of the second window. The distal portion of the first removable probe may further include a tissue collection device near a trailing edge of the cutting tool, the tissue collection device being configured to selectively extend out of and retract into the first window. The proximal portion of the first removable probe may include a tissue collection device extending means, the tissue collection device extending means being adapted to enable the tissue collection device to extend out of and to retract within the first window independently of the cutting tool. The tissue collection device may be coupled to the cutting tool and the cutting tool extending means may also be configured to selectively extend the tissue collection device out of the first window and retract the tissue collection device into the first window as the cutting tool is extended and retracted, respectively. The first removable probe may include an insulator between the tissue collection device and the cutting tool. The insulator may include an air gap and/or an insulating material attached to and separating the cutting tool from the tissue collection device. The first removable probe may define one or more internal lumens that terminate near the distal portion as an opening formed in a surface of the first removable probe, the opening being adapted to deliver a pharmaceutical agent and/or to provide suction.
A third removable probe may be provided, the third removable probe being configured to fit at least partially within the tubular member and including an imaging device mounted therein. The imaging device may include an ultrasound sensor, such as a linear array of ultrasound transducers, for example. The ultrasound sensor may be disposed near a distal tip of the third removable probe and away from the cutting tool, so that the ultrasound sensor sweeps a plane ahead of the cutting tool as the tubular member rotates. The ultrasound sensor may be tuned within the range from about 7.5 MHz to about 20 MHz. The ultrasound sensor may be disposed within the tubular member at an angle a relative to the cutting tool, the angle xcex1 being no smaller than that necessary to effectively control the operation of the cutting tool in response to information gathered from the ultrasound transducer as the tubular member rotates. For example, the angle xcex1 may be less than about 90 degrees.
The tubular member, first removable probe, the second removable probe and/or the third removable may be configured for a single use and may be disposable.
The present invention is also a soft tissue treatment method, comprising the steps of inserting a generally tubular member into the soft tissue, the tubular member defining a first window in a surface thereof, the tubular member being configured to accept a removable probe inserted therein; inserting a first removable probe into the tubular member, the first removable probe including a cutting tool that is adapted to face out of the first window; selectively activating the cutting tool to cut a tissue specimen while rotating the tubular member within the tissue; removing the first removable probe from the tubular member while the tubular member stays in place; inserting a second removable probe into the tubular member, the second removable probe including a tissue collection device that is adapted to face out of the first window, and selectively activating the tissue collection device to encapsulate the tissue specimen rotating the tubular member.
The first removable probe may be inserted into the tubular member before the tubular member is inserted into the soft tissue. The method may further include the steps of inserting a third removable probe into the tubular member, the third removable probe including an imaging device therein that is configured to face out of the first window, and rotating the tubular member while activating the imaging device to image the soft tissue at least one of before and after the tissue collection device is activated. The tubular member may define a second window in the surface thereof and the method may further include the steps of inserting a third removable probe into the tubular member, the third removable probe including an imaging device therein that is configured to face out of the second window, and rotating the tubular member while activating the imaging device to image the soft tissue at least one of before, during and after the tissue collection device is activated.
Steps may be carried out to display information received from the imaging device on a display device and to vary the operation of the cutting tool and/or the tissue collection device during the first and/or second activating steps based upon the displayed information from the imaging device. The cutting tool may include an electrosurgical blade and the method may further include the step of varying a power applied to the electrosurgical blade based upon information received from the imaging device or feedback to the RF generator. A step of stabilizing the soft tissue in an uncompressed state prior to the first inserting step may also be carried out.
The tubular member and/or the first removable probe may define an internal lumen and a plurality of through holes in fluid communication with the internal lumen, and the method may further comprise one or more of the following steps: delivering a pharmaceutical agent to the tissue via the plurality of through holes, and suctioning smoke and/or fluids from the soft tissue via the plurality of through holes.
The present invention may also be viewed as a soft tissue treatment method, comprising the steps of inserting a generally tubular member into the soft tissue, the tubular member defining a first window in a surface thereof, the tubular member being configured to accept a removable probe inserted therein; inserting a first removable probe into the tubular member, the first removable probe including a cutting tool and a tissue collection device that are adapted to face out of the first window; selectively activating the cutting tool to cut a tissue specimen while rotating the tubular member within the soft tissue, and selectively activating the tissue collection device to encapsulate the tissue specimen while rotating the tubular member.
The first removable probe may be inserted into the tubular member before the tubular member is inserted into the soft tissue. The tubular member may define a second window in the surface thereof and the method may further include the steps of inserting a second removable probe into the tubular member, the second removable probe including an imaging device therein that is configured to face out of the second window, and rotating the tubular member while activating the imaging device to image the soft tissue at least one of before, during and after at least one of the cutting tool and the tissue collection device are activated. The method may also include the steps of displaying information received from the imaging device on a display device; and varying an operation of at least one of the cutting tool and the tissue collection device during at least one the first and second rotating steps based upon the displayed information from the imaging device.
The first and second activating steps may be carried out simultaneously and the cutting tool and the tissue collection device may be coupled to one another. Alternatively, the first and second activating steps may be carried out simultaneously or consecutively and the cutting tool and the tissue collection device may be activated independently of one another.
According to another embodiment thereof, the present invention is also an excisional biopsy system for soft tissue, comprising a tubular member defining a first, a second and a third window near a distal tip thereof; a first removable probe comprising a proximal portion that includes cutting tool extending means, a distal portion and a cutting tool near the distal portion, the first removable probe being configured to fit at least partially within the tubular member to enable the cutting tool to selectively bow out of and to retract within the first window when the cutting tool extending means are activated; a second removable probe comprising a proximal section including a tissue collection device extending means and a distal section including a tissue collection device, the second removable probe being configured to fit at least partially within the tubular member to enable the tissue collection device to extend out of and to retract within the second window when the tissue collection device extending means are activated, and a third removable probe, the third removable probe being configured to fit at least partially within the tubular member and including an imaging device mounted therein that is configured to face out of the third window.
The present invention may also be viewed as an excisional biopsy system for soft tissue, comprising a tubular member defining a first and a second window near a distal tip thereof, a first removable probe comprising a proximal portion and a distal portion, the proximal portion including a tool extending means, the distal portion including a cutting tool and a tissue collection tool, the first removable probe being configured to fit at least partially within the tubular member to enable the cutting and tissue collection tools to selectively extend out of and to retract within the first window when the tool extending means are activated, and a second removable probe, the third removable probe being configured to fit at least partially within the tubular member and including an imaging device mounted therein that is configured to face out of the second window.
The cutting and tissue collection tools may be mechanically coupled to one another. The cutting and tissue collection tools may also be independently activated and the tool extending means may include a cutting tool extending means operative to extend and to retract the cutting tool out of and into the first window and a tissue collection extending means operative to extend and to retract the tissue collection tool into and out of the first window.